This invention discloses an apparatus for seaming of carpets. It is known in the art to join two pieces of carpet over a piece of padding, by means of a heat-activated adhesive tape disposed along the seam. Carpet seaming tape has disposed upon it adhesive material which melts when heat is applied. While the adhesive still is in the molten state, two pieces of carpet can be joined along the tape to create a seam. The hot adhesive cools and hardens very quickly.
The means which has been commonly used to join carpet pieces has typically been a hand-operated electric iron, usually having a rectangular base. The iron is moved along the adhesive tape, causing the adhesive to melt, whereupon the pieces of carpet are pressed down upon the tape.
Several problems occur when using apparatus of the type described above. The high heat developed by the iron, which is typically heated to temperatures of about 380.degree.-400.degree. F., tends to damage the padding beneath the adhesive tape, particularly if the adhesive tape is thin and uninsulated. The heat also can damage the polypropylene backing of the carpet. Also, molten adhesive tends to seep through the tape, or around it, causing the carpet to adhere to the padding underneath. When the carpet is stretched, after seaming, the adhesion to the padding causes the carpet to become wrinkled. Another problem encountered in the use of apparatus of the type known in the prior art is due to the pressure applied by the operator of the iron to the adhesive tape. Unless the tape is reasonably thick and sturdy, the tape may break under the pressure applied by the operator while pressing down on the iron.
Still another problem encountered in the prior art is the inability of an operator to know how fast to move the iron along the adhesive tape. It is desirable to move the iron quickly along the adhesive tape, thereby reducing the time and labor costs required to complete a job. But in order to shorten the time needed, one needs to increase the temperature of the iron, thereby increasing the risk that, if the iron is not moved sufficiently rapidly, excessive heat will cause damage, for the reasons described above. Also, even if the temperature of the iron is not too high, the iron, if moved too slowly, may still cause heat damage. The present invention includes a feature which tells the operator of the apparatus how fast to move the iron.